In December 2015, Stevens travelled to a Peruvian retreat in the amazon called Phoenix Ayahuasca, seeking a cure for a skin condition he'd battled for years.

"My hair started to fall out in circular patches and my arm was covered in a rash," said Stevens.

Stevens, who was 29 years old at the time, believed ayahuasca would help. It's a hallucinogenic drink used as a cure for a variety of ailments by indigenous tribes in Peru.

Ayahuasca is also being used by westerners looking for a mind-altering experience.

Stevens said the man who attacked him, British tourist Unais Gomes, had taken a double dose of the drug.

"I could hear him screaming the name Yahowe," said Stevens. "And I was very concerned, because he was just screaming it at the top of his lungs."

Stevens said, at the time, he was meditating away from the group, fully sober. Hearing the screams, he came out to see what was wrong and spotted Gomes.

"He said, ‘you are Yahowe, you are Yahowe. It's time to get your demons out brother, it's time to get your demons out’," said Stevens.

Stevens said that’s when Gomes attacked him suddenly. The Winnipegger ran for help in the kitchen area, where he said the British tourist grabbed a knife and tried to stab him.

"He swiped at me, and he hit the table and his knife broke," said Stevens. “I went to hit him with the pot and I hit him in the side of the body, and my pot broke. And that's when he picked up this big butcher knife."

They fought over the knife, before two workers from the retreat came in and tried to grab Gomes.

Stevens said he wrestled the knife away, before Gomes went after the workers.

"What I was saying to myself is, ‘if he gets this knife back, he's either going to kill me or the other two men here,’ said Stevens. "That's when I made the decision to stab him."

Stevens stabbed Gomes twice, killing the British tourist.

The Winnipegger was arrested and held by Peruvian authorities for twenty four hours, after witnesses to the attack were questioned.

Stevens said all he's left with now is a deep feeling of sadness over the death of man he once called a brother.